Sheet feeding arrangement for rotary printing machines



H. GERLACH April 7, 1953 SHEET FEEDING ARRANGEMENT FOR ROTARY PRINTINGMACHINES Filed Sept. 23, 1948 2 SHEETS-SHEET I Muenfar #060 62752660-.(a*%m Afforney H. GERLACH- April 7, 1953 SHEET FEEDING ARRANGEMENTFOR ROTARY PRINTING MACHINES Filed Sept. 23, 1948 2 SHEETS-SHEET 2 #060G5; new

7nvenf0r fly 1 (am Afro/nay Patented Apr. 7, 1953 SHEET FEEDINGARRANGEMENT FOR ROTARY PRINTING MACHINES Hugo Gerlach, London, England,assignor to Block & Anderson Limited, London, England, a corporation ofGreat Britain Application September 23, 1948, Serial No. 50,682 In GreatBritain September 27, 1947 4 Claims.

This invention relates to sheet feeding arrangements for rotary printingmachines and has for its main object to provide an improved feedingarrangement which is positive in operation and can be timed in relationto the rotary printing couple so as to ensure correct registrationbetween the fed sheet and the printing surface of the printing roller.The sheet feeding arrangement is adapted particularly for use in rotaryhectographic printing machines in which the matter to be printed (orcopied) is provided in mirror script in hectographic ink on a sheet (themaster) secured to the printing drum, the copies being obtained bypassing sheets moistened with a solvent for the hectographic ink betweenthe printing drum and a co-operating pressure roller.

In sheet-feeding arrangements for rotary printing machines it is alreadyknown to provide intermittently driven feed rollers which initially aredriven to advance the copy sheet to the bite of the printing couple andthereafter the sheet is entrained by the rotation of the printingcouple, the drive to the feed rollers being suspended. Such a feedarrangement is described and shown for example in my prior U. S.application Ser. No. 655,760, filed March 20, 1946, in which theintermittent drive is obtained by the intermittent engagement of atoothed segment secured to the printing drum with a toothed wheel indriving association with one of the'feed rollers. With such anarrangement it is difficult to ensure that the driven feed roller comesto rest in a predetermined position, and to avoid undue noise and wearduring operation, so that particularly after the machine has been in usefor some time, trouble may be encountered in obtaining properregistration between the copy sheet and the matter to be copied.Accurate registration is of particular importance when the copy isrequired on a pre-printed form.

According to the present invention, the drive of the feed-rollers isderived from the rotation of the printing couple by means including atoothed sector which is oscillated by the rotation of the printingcouple and which is in constant engagement with a toothed wheelassociated with a shaft by means of a uni-directional coupling orfree-wheel device, whereby the shaft is driven when the toothed sectormoves in one direction, whereas the toothed wheel rotates freelyrelatively to the shaft when the toothed sector moves in the otherdirection. The said shaft may carry the driven feed roller or may beconnected by positive gearing to a shaft carrying the driven feedroller.

In order that the invention may be more readily understood, referencewill now be had to the accompanying drawings, which show, by way ofexample, a preferred embodiment as applied to a rotary hectographi-ccopying machine, and in which:

Figure 1 is a general side view of the machine in one extreme positionof the adjustment.

Figure 2 is a fragmentary top plan view of the adjusting mechanism asshown in Figure 1.

Figure 3 is a fragmentary side view in the other extreme position ofadjustment.

Figure 4 is a fragmentary cross section showing a detail on an enlargedscale.

The printing drum or master drum l on which is secured a master sheetbearing in mirror script in hectographic ink the matter to bereproduced, may be rotated in any convenient manner with either a handor motor drive, as is well known in such hectographic copying machines.Co-operating with the master drum l to form the printing couple is apressure roller 2. The drum l and the roller 2 are journalled inbearings in the side frames 3 of the machine. The sheets to receive thecopies are fed singly to the printing couple by a pair of feed rollers4, 5, the roller 4 being the driven roller. A supply of copy sheets or asingle sheet, as desired, is placed on the feed table 6 ,which is at thefront of the machine (the righthand end of Figures 1 and 3) and thesheet (or uppermost sheet of a pile) is advanced to the bite of the feedrollers 4, 5 where the line of contact between the rollers forms alocating stop for the leading edge of the sheet. On'operating themachine, the printing drum I is rotated, the feed rollers d, 5 advancethe sheet until the leading edge is gripped by the printing couple andin the continued rotation of the drum 1 the sheet is entrained therebyand brought into contact with,

the hectographic master. In its passage to the drum I, the sheet ismoistened by a solvent for the hectographie ink, any convenientmoistening device being utilised. Preferably a moistening deviceaccording to my said U. S. application Ser. No. 655,760 is employed, inwhich the solvent is applied to an upwardly inclined capillary pad andis transferred from the upper edge of the pad to the upper feed roller4. This moistening device is fully described and illustrated in theapplication referred to, and as it does not constitute part of thepresent invention it will not be further described herein. After passingbetween the master drum and the pressure roller to have the copy printedon it, the sheet is received by the delivery tray at the rear of themachine.

To derive the rotation of the feed rollers 4, 5

from the rotation of the master drum I, a cam 8 is secured on the shaftof the drum or to the end face of the drum so as to rotate therewith. Arocker 9, pivotally mounted on the side frame 3 of the machine, carriesa cam follower roller H3 which by means of a spring H is held in contactwith the edge of the came 3. The spring 1! extends between the rocker 9and an anchor post 12 mounted on the side frame 3. To ensure the returnof the rocker 9, it carries a second roller I3 which by engagement withthe earn 8 positively restores the rocker if the spring H has failed tomaintain the follower roller ii] in contact with the cam. As the cam 8and the rocker 9 are arranged on opposite sides of the side frame 3, theside frame is provided with elongated slots l4, [5 through which therollers l3 and i3 extend. The oscillatory movement of the rocker 9 istransmitted by way of a link it provided with a pin I1, preferablyfurnished with a roller it as shown, which engages with a toothed sectorit! pivotally mounted on a pin 29 carried by the side frame 3. In theembodiment shown, the roller I8 is received in a substantially radialslot 2| in the toothed sector l9. By means of the connecting link It,the toothed sector it is caused to rock simultaneously with the rockert. The toothed sector i9 is constantly in mesh with a pinion wheel 22mounted on a shaft 23 with the interposition of a unidirectionalcoupling or free wheel device 24. This device may be of any convenientconstruction, that shown being assumed to be of the well-known wedgingroller type, whereby in the counter-clockwise movement of the toothedsector l9 as viewed in Figures 1 and 3, the shaft 23 is driven, whereasin the opposite movement of the sector IS the pinion 22 rotatesrelatively to the shaft 23. The arcuate length of the toothed sector itis so chosen in relation to the movement which can be imparted from thecam B by way of the link iii, that the toothed sector i9 is constantlyin mesh with the pinion 22. The drive transmitted to the feed rollershaft 23 and thus to the directly driven feed roller 4 and theco-operating feed roller 5 is chosen so as to be at least sufiicient toadvance the sheet from the line of contact of the feed rollers 4, 5, tothe line of contact of the printing couple I, 2. Once the sheet has beenengaged by the printing couple it is entrained thereby, this beingpermitted by the free wheel device 24. Due to this device also, thetoothed sector I9 can revert to its position as shown in Figures 1 and3, while the entrained sheet causes the feed rollers 4, 5 to continue torotate in the feed direction.

With the drive to the feed rollers as described above, it is desirableto be able to adjust the moment of initiation of the feed drive and/orthe rate of drive so as to afford the possibility of regulating theregistration of the copy sheet in relation to the matter to be copied.This is of particular importance when the copy is to be taken on a ruledor otherwise pre-printed sheet. It is desirable also that thisadjustment of registration should be possible between consecutiveprinting operations without the services of a trained mechanic. Thisresult is achieved with the adjusting mechanism which is shown in theaccompanying drawings and which will now be bescribed.

The connecting link It extends beyond the toothed sector it towards thefront of the machine and adjacent its forward end is provided with alongitudinally extending slot 25. A pin 26 on a pivotal member 21carried by a pivot pin 28 engages in the slot 25, so that by pivotationof the member 2! about its pivot pin 28, the pin 26 is displaced in theslot 25 and thereby raises or lowers this end of the link I6. The rollerI8 is correspondingly raised or lowered in the slot 2| in the toothedsector 19. When the roller [8 is towards the upper end of the slot 2! asin Figure 1, the fixed throw of the rocker 9 causes a smaller angularmovement of the sector 19 and thus a slower feed movement of the feedrollers 4, 5 in relation to the peripheral speed of the master drum l,whereas when the roller [8 is towards the lower end of the slot 2| as inFigure 3, there is a larger angular movement of the sector l9 and afaster feed movement of the feed rollers 4, 5 in relation to theperipheral speed of the master drum l. Thus, starting from a given restposition of the master drum i, it is possible to alter the registration,i. e. the position of the leading edge of the copy sheet in relation tothe leading edge of the master sheet.

For the adjustment of the pin 26 in the slot 25, the pivotal member 21is connected to a threaded rod 3! carrying a milled adjusting nut 32.This adjusting nut is located between fixed cheeks 33 secured to theside frame 3, so that rotation of the nut 32 causes corresponding axialmovement of the threaded rod 3! and thus corresponding pivotal movementof the member 2?. Lock nuts 3% on the rod 3i serve to limit the maximumtravel of the rod 3! and consequently prevent damage to the adjustingdevice by attempts to adjust beyond the available amounts.

To enable the degree of adjustment to be observed, a graduated scale 36is secured to the side frame 3 and a pointer or index 35 mounted on thepivotal member 21 is arranged to travel over the scale. The whole of themechanism arranged on the outside of the side frame 3 may be concealedin a cover plate provided with a window to enable the scale 35 and thepointer 35 to be read, and an aperture to permit the outermost part ofthe milled nut 2 to project for fingertip manipulation by the operator.The contour of such a cover plate is indicated at 31 in Figure 2 inchain-dotted lines.

I claim:

1. A printing machine comprising in combination a printing couple and apair of sheet feed rollers, a pinion in unidirectional coupling with oneroller, a toothed sector oscillatable on the machine in constant meshwith said pinion, a rocker oscillatable on the machine in constantdriven engagement with an element of the printing couple, a link inpivotal connection with said rocker and with the toothed sector foroscillation of the sector in response to oscillation of the rocker, andmeans for moving said link to dispose its connection with the sectorselectively at different distances radially of the sector to vary theextent of oscillation of the sector.

2. A printing machine comprising in combination a printing couple and apair of sheet feed rollers, a pinion in unidirectional coupling with oneroller, a toothed sector oscillatable on the machine in constant meshwith said. pinion, a rocker oscillatable on the machine in constantpositive driven engagement with an element of the printing couple, alink in positive connection with both said rocker and the toothed sectorfor oscillation of the sector in response to oscillation of the rocker,and manually operative means in constant engagement with a portion ofthe link for shifting the link to dispose its connection with the sectorselectively at difierent distances 5 radially of the sector foradjustment of the feed roller operating stroke of the sector.

3. A printing machine comprising in combination a printing couple and apair of sheet feed rollers, a pinion in unidirectional coupling with oneroller, a toothed sector oscillatable on the machine in constant meshwith said pinion, a rocker oscillatable on the machine in constantpositive driven engagement with an element of the printing couple, alink in positive connection with both said rocker and the toothed sectorfor oscillation of the sector in response to oscillation of the rocker,said link at one end extending beyond the rocker, and an adjustmentmember pivoted on the machine and having a stud slidably engaging theextending end of the link to shift the link radially of the toothedsector in response to movement of the member, whereby to shift theconnection between the link and sector radially of the sector forselectively varying the REFERENCES CITED The following references are ofrecord in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,046,901 Kirby July 7, 19362,089,979 Nigra Aug. 17, 1937 2,185,138 Flanigan -1 Jan. 2, 19402,188,600 Kropp Jan. 30, 1940 2,204,715 Wimmer June 18, 1940 2,262,915

Bobst Nov. 18, 1941

